Listar UJI: Investigación por autoría "a457b1fd-fc86-4e12-a7d2-396cd155d11d"
Mostrando ítems 1-20 de 26
-
A dynamic model of a shell-and-tube condenser operating in a vapour compression refrigeration plant
Llopis, Rodrigo; Cabello López, Ramón; Torrella Alcaraz, Enrique Elsevier (2008)This work presents a mathematical model of a shell-and-tube condenser based on mass continuity, energy conservation and heat transfer physical fundamentals, whose methodology can be easily adapted for modelling any type ... -
A general methodology for energy comparison of intermediate configurations in two-stage vapour compression refrigeration systems
Torrella Alcaraz, Enrique; Larumbe, J. A.; Cabello López, Ramón; Llopis, Rodrigo; Sánchez García-Vacas, Daniel Elsevier (2011-07)The aim of the present paper is to describe a general methodology suitable for analysing any intermediate configuration considered in staged vapour compression refrigeration cycles. This general methodology only depends ... -
A simplified model for shell-and-tubes heat exchangers: Practical application
Vera García, Francisco José; García Cascales, J.R.; Gonzálvez Maciá, J.; Cabello López, Ramón; Llopis, Rodrigo; Sánchez García-Vacas, Daniel; Torrella Alcaraz, Enrique Elsevier (2010)In this paper, a simplified model for the study of shell-and-tubes heat exchangers (HXs) is proposed. The model aims to agree with the HXs when they are working as condensers or evaporators. Despite its simplicity, the ... -
Comparative evaluation of the intermediate systems employed in two-stage refrigeration cycles driven by compound compressors
Cabello López, Ramón; Torrella Alcaraz, Enrique; Llopis, Rodrigo; Sánchez García-Vacas, Daniel Elsevier (2010)This work presents an experimental evaluation, from an energy analysis point of view, for two of the most used inter-stage systems in two-stage vapour compression cycles driven by compound compressors: the direct liquid ... -
Development and validation of a finite element model for water – CO2 coaxial gas-coolers
Sánchez García-Vacas, Daniel; Cabello López, Ramón; Llopis, Rodrigo; Torrella Alcaraz, Enrique Elsevier (2012-05)The gas-cooler heat exchanger is a characteristic device of the refrigeration plants that use CO2 as the working fluid in transcritical conditions. The proper gas-cooler sizing, allows getting the maximum effectiveness in ... -
Energetic evaluation of a CO2 refrigeration plant working in supercritical and subcritical conditions
Sánchez García-Vacas, Daniel; Patiño Pérez, Jorge; Sanz Kock, Carlos; Llopis, Rodrigo; Cabello López, Ramón; Torrella Alcaraz, Enrique Elsevier (2014-05)Unlike other refrigerants, R744 (or carbon dioxide) has a very low critical temperature (30.98 °C) which hampers working in subcritical conditions especially when the environment is used as a heat rejection sink. Accordingly, ... -
Energetic evaluation of an internal heat exchanger in a CO2 transcritical refrigeration plant using experimental data
Torrella Alcaraz, Enrique; Sánchez García-Vacas, Daniel; Llopis, Rodrigo; Cabello López, Ramón Elsevier (2011)The performance of an Internal Heat Exchanger (IHX) operating in a CO2 transcritical refrigeration plant is analysed, from an energetic point of view, in this work. The evaluation is based on experimental data by contrasting ... -
Energy and environmental comparison of two-stage solutions for commercial refrigeration at low temperature: Fluids and systems
Llopis, Rodrigo; Sánchez García-Vacas, Daniel; Sanz Kock, Carlos; Cabello López, Ramón; Torrella Alcaraz, Enrique Elsevier (2015-01-15)International agreements will restrict in the near future the use of high-GWP refrigerants in Europe. These restrictions will favour the implantation of refrigeration systems with low-GWP fluids, especially in applications ... -
Energy evaluation of R152a as drop in replacement for R134a in cascade refrigeration plants
Cabello López, Ramón; Sánchez García-Vacas, Daniel; Llopis, Rodrigo; Catalán-Gil, Jesús; Nebot-Andres, Laura; Torrella Alcaraz, Enrique Elsevier (2017-01)An experimental comparison has been performed of a cascade refrigeration facility working with the refrigerant pairs R134a/R744 and R152a/R744. This kind of facility is suitable for industrial and commercial refrigeration ... -
Energy influence of the IHX with R22 drop-in and long-term substitutes in refrigeration plants
Cabello López, Ramón; Torrella Alcaraz, Enrique; Llopis, Rodrigo; Sánchez García-Vacas, Daniel; Larumbe, J. A. Elsevier (2013-01-10)This work focuses on the investigation of new drop-in or long-term refrigerants for low evaporating temperatures that can be used as substitutes for HCFC-22, which is gradually being phased-out. This process is already in ... -
Energy perfomance evaluation of R1234YF, R1234ze (E), R6600a, R290 and R152a as low-GWP R134a alternatives
Sánchez García-Vacas, Daniel; Cabello López, Ramón; Llopis, Rodrigo; Arauzo Pérez, Ivan; Catalán-Gil, Jesús; Torrella Alcaraz, Enrique Elsevier (2017-02)In 2014, the Directive 517/2014 was introduced by European Parliament to reduce the use of high-GWP greenhouse gases in the European area in order to limit global climate change in accordance with the objectives marked by ... -
Experimental analyis of energy performance of modified single-stage CO2 transcritical vapour compression cycles based on vapour injection in the suction line
Sánchez García-Vacas, Daniel; Cabello López, Ramón; Patiño Pérez, Jorge; Llopis, Rodrigo; Torrella Alcaraz, Enrique Elsevier (2012-12)This work presents the experimental evaluation of the energy performance of a modified single-stage CO2 transcritical refrigeration plant with an internal heat exchanger (IHX) based on vapour injection in suction line. ... -
Experimental evaluation of a R134a/CO2 cascade refrigeration plant
Sanz Kock, Carlos; Llopis, Rodrigo; Sánchez García-Vacas, Daniel; Cabello López, Ramón; Torrella Alcaraz, Enrique Elsevier (2014)We present the experimental evaluation of a R134a/CO2 cascade refrigeration plant designed for low evaporation temperature in commercial refrigeration applications. The test bench incorporates two single- stage vapour ... -
Experimental evaluation of an Internal Heat Exchanger in a CO2 subcritical refrigeration cycle with gas-cooler
Llopis, Rodrigo; Sanz Kock, Carlos; Cabello López, Ramón; Sánchez García-Vacas, Daniel; Torrella Alcaraz, Enrique Elsevier (2015-04-05)We present the experimental evaluation of an internal heat exchanger or suction-line/liquid-line heat exchanger in a CO2 subcritical refrigeration plant with gas-cooler. The plant, driven by a 1.5kW CO2 semi hermetic ... -
Experimental evaluation of HCFC-22 replacement by the drop-in fluids HFC-422A and HFC-417B for low temperature refrigeration applications
Llopis, Rodrigo; Cabello López, Ramón; Sánchez García-Vacas, Daniel; Torrella Alcaraz, Enrique; Patiño Pérez, Jorge; Sánchez, J. G. Elsevier (2011-05)The Regulation CE-1005/2009 has banned the use of virgin HCFC-22 in Europe from the 31st December 2009, because it contains chlorine, although its use is allowed up to the 31st December 2014 if it is recycled. Now, ... -
Experimental evaluation of the energy efficiency of a CO2 refrigerating plant working in transcritical conditions
Cabello López, Ramón; Sánchez García-Vacas, Daniel; Llopis, Rodrigo; Torrella Alcaraz, Enrique (2008)This work presents the experimental evaluation of the energy efficiency and optimal gas-cooler pressures of a single-stage refrigerating plant working with carbon dioxide as refrigerant in transcritical conditions. The ... -
Experimental Evaluation of the Energy Performance of an Air Vortex Tube when the Inlet Parameters are Varied
Torrella Alcaraz, Enrique; Patiño Pérez, Jorge; Sánchez García-Vacas, Daniel; Llopis, Rodrigo; Cabello López, Ramón Bentham Open (2013)he paper presents the analysis of the energy performance of an air vortex cooling tube under variations of the air inlet properties, with t hree independent experimental tests validated through the energy balance ... -
Experimental evaluation of the inter-stage conditions of a two-stage refrigeration cycle using a compound compressor
Torrella Alcaraz, Enrique; Llopis, Rodrigo; Cabello López, Ramón Elsevier (2009)The aim of the present paper is to detail an analysis, based on experimental data, of the inter-stage working conditions of a two-stage vapour compression facility equipped with a compound compressor, which operates with ... -
HCFC-22 replacement with drop-in and retrofit HFC refrigernants ina a two-stage refrigeration plant for low temperature
Sánchez García-Vacas, Daniel; Cabello López, Ramón; Llopis, Rodrigo; Torrella Alcaraz, Enrique Elsevier (2012)The world community has committed to eliminate the HCFC-22 refrigerant to a series of deadlines according to the agreements taken during the 19th Montreal Protocol meeting in September 2007. This phase-out, which is already ... -
Influence of the superheat associated to a semihermetic compressor of a transcritical CO<sub>2</sub> refrigeration plant
Sánchez García-Vacas, Daniel; Torrella Alcaraz, Enrique; Cabello López, Ramón; Llopis, Rodrigo Elsevier (2010)This work evaluates, from an energetic point of view, the effects of the superheat caused in the refrigerant by the electric motor cooling (SH<sub>SC</sub>) in a semihermetic compressor installed in an experimental ...